Since 2002, the Colorado Department of Public Health and Environment (CDPHE) has been part of a multi-state (Arizona, Colorado, Iowa, New York, Georgia and Hawaii) cooperative agreement with the Centers for Disease Control and Prevention (CDC), the Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet) that models the infrastructure necessary to understand the epidemiology of genetic disorders from a public health perspective and gathers data about issues related to outcomes and health services. As part of MD STARnet, we have conducted population-based surveillance and epidemiologic research of Duchenne and Becker Muscular Dystrophy (DBMD) and published several articles to disseminate the findings of this work. These articles have covered areas such as age at diagnosis, development of a standard surveillance case definition, use of steroids, and prevalence and mortality and have contributed to the scientific and clinical understanding of DBMD in the United States. The Specific Aims and Activities (shown at the end of this document) in this proposal will allow the MD STARnet sites to: 1) continue to collect focused data and publish reports on the MDSTARnet population to further inform scientific and clinical questions about DBMD plus seven other muscular dystrophies, including information about survival, needs, quality of life, and the important transition period for adolescents and adults with these conditions; 2) collect and disseminate important 'lessons learned' from the first network in the United States to design and implement population-based surveillance and research for these conditions; 3) pilot a longitudinal model to determine the prevalence, demographics, healthcare coverage, and locations of care for Pompe disease and evaluate and report the results of this activity utilizing electronic data bases as well as newborn screening data. Using this existing model and Network is an efficient way to gain important insights about a heterogeneous and complex group of conditions.